Disclosed herein, in various embodiments, are methods for forming components of electronic devices, such as organic thin-film transistors. Components and devices made from or using these methods are also disclosed.
Fabrication of electronic circuit elements using liquid deposition techniques may be beneficial as such techniques provide potentially low-cost alternatives to conventional mainstream amorphous silicon technologies for electronic applications such as thin film transistors (TFTs), light-emitting diodes (LEDs), RFID tags, photovoltaics, etc. However, the deposition and/or patterning of functional electrodes, pixel pads, and conductive traces, lines and tracks which meet the conductivity, processing, and cost requirements for practical applications have been a great challenge. The metal, silver, is of particular interest as conductive elements for electronic devices because silver is much lower in cost than gold and it possesses much better environmental stability than copper.
TFTs are generally composed of a supporting substrate, three electrically conductive electrodes (gate, source and drain electrodes), a channel semiconducting layer, and an electrically insulating gate dielectric layer separating the gate electrode from the semiconducting layer.
In particular, printing channels having a short length or gap consistently and reproducibly is very difficult at micrometer distances, yet is needed for organic thin-film transistors (OTFTs). For example, a channel between a source electrode and a drain electrode may be as small as 50 microns. It would be desirable to provide processes that allow for consistent production of channels on such scales.
One method is to pre-form a bank or banks to confine the location of the materials to be deposited. Using photolithographic methods to form the bank(s) could lead to small gaps. However, this approach complicates the fabrication process and increases manufacturing costs accordingly.